Shoe sewing machine



4July 29,1941. 'QR HMS 2,250,953

SHOE SEWIVNG MACHINE l Filed Mayas, 1939 movement ofthe auxiliary take-up'.

` Patented iulry 29, 1941 N'er {l-FICE j snor: SEWING MACHINE tto R.'4 Haas, North Beverly, Mass.,

'assigner' to United Shoe Machinery Corporation, Borough of Flemington, N. Jersey J.,- acorporation of- New Application May 26, 1939, SerialNo. `275;!)42 2 Claims. (Cl. 11257) The present invention relates to improvements in heavily constructed shoe sewing machines of the wax thread type and is herein illustrated as being embodied in a curved hook needle lockstitch sewing machine similar -to that disclosed in prior U. S. Letters Patent of French and Meyer No. 473,870, of April 26, 1892, having mairi take-up acting to set each stitch, and an auxthread is being applied to the needle hook. Inv

viliary take-up to assist thel main take-up in con'- the sewing machine described in the patent rel ferred to, the auxiliary taire-up is -in the form of a spring actuated arm so arranged that when the stitch is being set by the main take-up, the auxiliary take-up is brought with a sudden impact against afixed stop which is provided on the machine frame to limit the thread giving.up

the auxiliary take-up is brought against the xed stop its velocity is relatively high, andas a result of the impact and the weight of the auxiliary take-up' arm, there is a tendency for the auxiliary take-up to -rebound with vibratory eects', the tension on the thread together with the spring actionof the auxiliary take-up causing the arm to vibrate excessively, at one or more particular frequencies. With the parts constructed as disclosed in the prior patent, thetextent of vibration of the auxiliary take-up 'when the machine is running at relatively moderate speeds may affect successive stitches in a seam to cause them to be set in an erratic manner. Accordingly, the present invention relates to the include a. hook needle, a needle looper and a take-up, of a spring actuated auxiliary take-up formed of synthetic resin materialarranged for movementtowards andfrom a iixed 'stop on the machine frame during operation of the looper in laying the thread in the' hook of the needle and t the stop with a instant the stitch is being set by the main-take- Just before up. Due'to the marked ability of the synthetic resin material to absorb impacts without caus-` ing a rebound and to itslower density as compared to iron or steel from which the auxiliary take-up of the patented machine iscomposed.- the tendency of a synthetic resin auxiliary takei up to vibrate excessively while each stitch is being set is reduced to such anextent 'that the stitches of a seam inserted. by a machine so equipped are more accurately and uniformly set in the work than of the patent. A

Other Yfeatures of the invention will be more clearly understood from the fllowing specifica,- tion and the accompanying ldrawing in which Figure 1 is a view in left hand side elevation of the front portion o f a machine embodying the presentinvention, and Figure'Z is aperspective view, on an enlargedscale, of the auxiliary takeup arm shown in'Figure 1.

The illustrated machine is similar, except as- I hereinafter describedjto thellockstitch outsole shoe vsewing machine disclosed inv the patent above referred to, the stitch-forming-devices'oi" which include a curved hook needle. 2, a 'curvedawl 4, a needle looper 6, a shuttle 8, a main take-up i0, a thread measuring arm or pull-off i2, a thread lock I l against whicheach stitch is set, and an` auxiliary take-up I. The machine.

` is intended to operate upon heavy leather materials such as the outsole indicated at Il of a.` shoe, and to formseacn stitch in the seam, the awl 4 isactuated'to penetrate the `work and the needle to follow the awl through the perforations thusmade until-the hook of the needle projectsv l through the work, When the needle is in this up thread. vand to maintained under a uniform light tension, the

provision in a shoe sewing machine of the wax l thread type. .the stitch-forming devices of which spring engaging a stud '28, on

position, the looper 8 through which the needle thread is guided moves about the hook `of the needle and lays the thread therein. During this movement of the looper the take-up I0 is giving insure that lthe thread is auxiliary take-up I6 is actuated yieldingly away from a fixed stop 20 extending from the frame of the machine'against the resistancev of a spring 22- coiled around a stud 24 on which the auxiliary take-up is fulcrumed. the other end of the the auxiliarytake-f up. The auxiliary take-up is inthe form o! an arm having perforations' at either end to receive the studs 24 and 26 respectively, and onthe stud 2l is rotatably mounted a thread guiding pulley or sheave 2l. To limit the movement of the aux- Sllbstantial impact at lthe iliary take-up arm under the action of the spring 22, there is threaded in the frame oi the machine 'those inserted by the machine nov rebound occurs.

a set screw 30 arranged to engage the upper side oi the take-up arm. To cooperate with the xed stop 20 against which the take-up arm is drawn by the tension on the thread as each stitch this, the auxiliary take-up moves away from the xed stop 20 and holds the thread yieldingly until a stitch-setting tension is applied by the main take-up to the thread. When a stitchsetting tension is applied to the thread, .the aux.- iliary take-up is moved rapidly against the xed stop 2l and, due to the shape and weight of the auxiliary take-up arm as well as to the yielding action of the spring 22 and the ability of the thread to stretch, there is a tendency for the auxiliary take-up arm to rebound from the stop 2l so that the tension on the threadwill not be the same as when the auxiliary take-up arm remains in stationary lposition against the xed stop. As a result the stitch being set may be drawn deeper into the materials of the outsole Il when a substantial rebound occurs than when The vibratory effects caused by the rebound may not occur uniformly with each stitch. but may vary with the speed at which the machine is running, with the tension and amount of stretch in the thread being used and other factors not under the immediate control of the operator.

To reduce the vibrating eiects of the auxiliary take-up in the machine of the present invention to a'ipoint where they-fno longer disturbthe posi- `tion to which the threads of stitches are drawn by the main take-up as the stitches are being set, the arm of the auxiliary take-up I6, which in the machine of the patent is composed of metal. is in the present machine replaced by an arm of substantially the same size and shape composed of synthetic resin material, suitably reenforced by textile fibres or sheets. vWith the use of synthetic resin materials. such as those of the phenolic or urea types. the lug` 32 on the auxiliary y take-up arm which engages the stop 2l absorbs to a `large extent the impact produced when the lug is brought against the stop during the setthetic resin material. to return to its original after a relatively'long interval as compared to the quick return of metallic materials to their original shapes and to the lower weight of the synthetic resin material, there is no substantial tendency for the auxiliary take-up arm to vibrate or to interfere with the setting of the stitch.

.The nature and scope oi the invention having been indicated, what is claimed is:

1. A shoe sewing machine having, in combination, a main frame.. a flxedf stop on the frame,

stitch forming devices including a hook needle and aneedle looper, a take-up, a thread measuring member, a thread lock against which each stitch isset. .and a spring actuated auxiliary take-up in the form of a pivoted arm of synthetic resin material having a projecting lug at one side arranged for movement by the tension on the thread during operation of the looper to lay thread in the hook of the needle to a position spaced from the fixed stop on the frame, during operation of the take-up to set the stitch to a position with the lug against said fixed stop at the instant the stitch is being set and when the thread lock is opened to a position again spaced from said iixed stop to take up the thread drawn olli from the supply by the thread measuring device, the lug being shaped when composedor said resin material to absorb a substantial proportion of the impact produced by the tension on the thread and to damp out any rebound as the stitch is being set.

2. A shoe sewing machine having, in combination, a main frame, a ilxed stop on the frame, stitch forming .devices including'a hook needle and a needle looper, a take-up, a thread measuring member, a thread lock against which each stitch is set, and a spring actuated auxiliary take-up in the form of a pivoted arm arranged fon-movement by the tension-"on the thread during operation of the looper to lay thread in the hook of the needle to a position spaced from the.

- thread measuring device, at least one of the conting of'each stitch. Due to the quality of syntacting surfaces comprised by saidiixed stop and said pivoted armr being composed of synthetic resin material to absorb a substantial proportion of that impact produced by the tension onthe thread and to damp out any rebound as the stitch is being set. y

v 1 OTTO R. HAAS. 

